It’s not a big issue, by the time they are loading/unloading the luggage, it can be done. It should be designed in a way that can be easily attached or detached, or even automated/robot based rails does the job quickly.
So for example: while booking you get to select those options, and while they load the luggage, an app on some crew tablet quickly arrange the seats and hit submit, the rails automatically do the jobs! Ycombinator, prepare that VC funds!! ;)
They get 22 minutes on most US domestic flights and that includes deboarding.
I don't know what your flying experience is, but mine is that you're lucky if the cleaning crews have a chance to make a quick sweep of the cabin before the next flight's occupants begin loading. I'm usually towards the back of the plane and the cleaning crews are already 10-15 rows into the plane by the time my row can exit.
There's no way, in my experience, that they'd have time for something like that. Especially since anything that moves will invariably have mechanical issues from time to time. I've had to sit in a broken seat before because they simply do not have time to fix it between flights.